This invention belongs to the art of synthetic organic chemistry, and provides a series of new antimicrobial heterocyclic compounds which are prepared by a novel process.
The 3-aminobenzo[b]thiophene-2-carbonitriles which are starting compounds for the process of this invention were disclosed by Beck and Yahner, J. Org. Chem. 39, 3440-41 (1974).
Beck and Yahner, J. Org. Chem. 38, 2450-52 (1973), showed the synthesis of 9-chloro-3-methyl[l]benzothieno[3,2-d]-v-triazin-4(H)-one by the diazotization of methyl 3-amino-4-chlorobenzo[b]thiophene-2-carboxamide. The same reference also described the synthesis of benzothienooxazinones and benzothienopyrimidinones.
Benzothieno[3,2-d]triazinones, wherein the substitutable carbon atom of the triazine ring is distant from the sulfur atom of the thiophene ring, are in the art. Sauter et al., Monatsch. Chem. 104, 1586-92 (1973) and U.S. Pat. No. 3,772,276. Henriksen et al., Acta. Chem. Scand. 26, 3342-46 (1972), taught thieno[3,2-e]-1,2,3-triazin-4-ones and thieno[3,4-e]-1,2,3-triazin-4-ones.